Unitized breaker point and chip capacitor assembly

ABSTRACT

A unitized breaker point and capacitor assembly for use in engine ignition systems. A chip capacitor is connected in parallel to the breaker point contacts and mounted so that it is substantially within the margins of the assembly and closely overlies the breaker arm.

United States Patent Seike Sept. 23, 1975 [54] UNITIZEI) BREAKER POINT AND CHIP 2,786,087 3/1957 McGrevy 200/31 A X CAPACITOR ASSEMBLY 3,612,963 10/1971 Piper et al.... 317/101 CC X 0 3,622,715 ll/l97l Jukes ZOO/l9 A X [75] In Helmut SeIke, Toledo, Ohio 3,646,301 2/1972 Huntzinger et al. 200/31 A x [73] Assignee: Eltra Corporation, Toledo, Ohio [22] Filed: Oct. 2, 1974 Primary Examiner.lames R, Scott [21] APPL No: 510,952 Attorney, Agent, or FzrmRobert H. Johnson [52] U.S. Cl 200/19 A; 123/1465; ZOO/3O A;

200/31 A; 317/256 [57] ABSTRACT [51] Int. Cl. HOIH 19/00 Field of s rc OO/l l 31 31 A unitized breaker point and capacitor assembly for 0 339/17 C use in engine ignition systems. A chip capacitor is conl23/146-5 149 6- A nected in parallel to the breaker point contacts and mounted so that it is substantially within the margins [56] References Cited of the assembly and closely overlies the breaker arm.

UNITED STATES PATENTS Alstrom 200/19 A X 4 Claims, 10 Drawing Figures US Patent Sept. 23,1975 Sheet 1 of 2 3,908,102

US Patent Sept. 23,1975 Sheet 2 of2 3,908,102

UNITIZED BREAKERPOINT ANDCHIP CAPACITOR ASSEMBLY BACKGROUND OF THE INVENTION assembly, it is necessary to connect a capacitor in par- 1 allel circuit with the contacts of the breaker point-assembly in .order to prevent the contacts from burning or Welding together due to arcing between'the contacts. Such an arrangement has been conventional fora long time. I d I It would be desirable to provide a unitized breaker point and capacitor assembly because, forexample, a mechanicwould have to handle and aser-vice station would have to stock only one part ,or assembly rather than two as is generally thesituation presently. There have been some attempts to provide such unitized assemblies as is illustrated by the disclosuresof U..S. Pat. Nos. 3,773,113; 2,786,087and 3,646,301.. In allof these patents it will be noted that a rolled paper and foil capacitor is utilized and that special distributors must be provided. The reduction in physical size of such capacitors is inherently limited because of the variousoperating parameters the capacitor must meet in an'engine ignition system application. As a result it has not been possible to provide a unitized breaker point and capacitor assembly which could be installed in -'the space provided for a breaker point assembly due to the size of the capacitor.

. Therefore, it is a-principal'object of my invention to provide a unitized breaker point and capacitorassembly which can be installed in an ignition system in'the space provided for a breaker point assembly only.

SUMMARY OF THE INVENTION In carrying out my invention "iii a preferred embodiment, there is provided a plate' to which a breaker arm is connected-for pivotal'movementl'A first contact is attached'to the arm and'a secondcontact is mounted on the plate. A spring is connected to the arm and a fastener connects the spring to a lug on 'the plate so that the first contact is-biased toward the'secondcontact. A chip capacitor is connectedin parallel circuit with the contacts and located within the perimeter of the plate and in close proximityto'the arm.

The above and other objects, features and advantages of my invention will be more easily understood by persons skilled in the art when the detailed description is taken in conjunction with the drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a plan view of a preferred embodiment of my invention,

FIG. 2 is a sectional view taken along line 22 of FIG. 1,

FIG. 3 is a sectional view taken along line 33 of FIG. 2,

FIG. 4 is an isometric view of a chip capacitor of the type utilized in my invention,

FIG. 5 is an end elevation of the capacitor holder,

FIG. 6 is a front elevation of the capacitor holder,

FIG. 7 is a sectional view taken along line 7-7 of FIG. 6,

' FIG. 8 is an isometric view of one of the spring clips and tabs embodied in the holder. shown in FIGS.

, through 7. v

FIG. 9 is an elevational view of an insulator utilized in my invention, and

. FIG 10 is a plan view of the same insulator.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIGS. 1, 2 and 3, the reference numeral 10 denotes a unitized breaker point-and capacitor assembly which includes .a support plate 12 of elec- -trically conductive material with-notches 14 and 16 whichare adapted to. accept machine screws so that assembly 10 can be securely fixedin position in aadistributor bowl, not shown. Extending upwardly from plate 12 is a pin 18 to whicha gap adjustment plate 20 of electrically conductive material is connected for pivotal movement. Plate 20 includes a pair of generally verticallyextending portions 22 and 24. Portion 22 carries a contact 26 and portion 24- threadably accepts a gap adjustment screw-28 which passes through an opening in a vertically extending portion 30 of support plate 12. Disposed between portions 24 and 30 and encircling the shank of screw 28 is a compression spring 32 which servesto bias thehead of screw 28 into abutment with portion 30, and thus maintain contact 26 in its adjusted position to provide the proper gap with the cooperating contact. Also connected to pin 18 for pivotal movement is a breaker arm 34 of electrically conductive material and which-carries at the outer end thereof a contact 36 which is aligned with contact 26. "Arm 34 also includes a portion 38 of suitable bearing material such as nylon. Projecting from portion 38 is a protuberance 40 which functions as a cam follower as is well known in this art.

:3 A leaf spring 42 is connected'to arm 34 by means of rivets'44-so that there is an electrical connection between spring 42 and arm 34 aswell as a physical con n'ection.

' Extending upwardly from support plate 12 is a lug 46 of electrically conductive material which may be connected to plate 12 by a suitable means, such as spot welding or riveting.

Spring 42 is connected to lug 46 by means of a bolt 48 and nut 50 'and biase s contact 36 toward contact 26. Bolt 48 includes a head 52 and a shank 54. Bolt 48 is electrically insulated from lug 46 by means of an insulator 56 which can best be seen in FIGS. 9 and 10. Bolt 48 is disposed so that shank 54 passes through a slot 58 in lug 46 and head 52 is disposed on the side of lug 46 opposite nut 50.

Referring now to FIGS. 9 and 10, insulator 56 includes a recess 58 adapted to receive head 52 of bolt 48, a slot 60 through which shaft 54 of bolt 48 passes and a stepped slot 62 which receives lug 46 and one of the tabs of the capacitor holder as will be explained shortly.

Referring now to FIGS. 4 through 8, a chip capacitor 64 is provided. Capacitor 64 is a generally rectangular wafer having a terminal 66 at one end and a terminal 68 at the opposite end. Capacitor 64 is a ceramic capacitor and uses, for example, barium titanate as the dielectric material. This capacitor must withstand transient voltages upwards of 400 volts, provide a capaciozone environment and withstand the shocks and vibration present in the distributor of an automotive ignition system. In addition to the considerable reduction in size, another advantage of chip capacitor 64 is that its series inductance is smaller than a rolled or wound paper and foil capacitor which means that the radio frequency interference suppression of the chip capacitor will be more effective.

Capacitor 64 is removably disposed in a holder 70 which includes a pair of spring clips 72 and 74. Clips 72 and 74 define a pair of inwardly facing slots 76 and 78, respectively, which are adapted to receive terminals 66 and 68 of capacitor 64. Clips 72 and 74 are connected together by a rigid molded-in-place dielectric plastic portion 80. Clip 72 includes a downwardly extending tab 82 and clip 74 includes a similarly shaped downwardly extending and parallel tab 84. Tabs 82 and 84 are arranged (see FIG. 2) so that when holder 70 is inplace tab 82 will be in electrical contact with spring 42and tab 84 will be in electrical contact with lug 46. With tabs 82 and 84 in the location shown in FIG. 2 it will be obvious that bolt 48 and nut 50 will maintain holder 70 in position and further that capacitor 64 will be located substantially entirely within the perimeter or margin of support plate 12 as viewed in FIG. 1. Further, capacitor 64 will be located in close proximity to and overlie breaker arm 34 with the result that the unitized assembly can be used in the space provided in a distributor fora breaker point set only.

The particular mounting of capacitor 64, utilizing the short tabs 82 and 84, has the further advantage of improving radio frequency interference suppression because the tabs replace the lead otherwise conventionally used with a wound capacitor, which lead provides a source of radio frequency interference.

As should now be apparent, when nut 50 is tightened on bolt 48 and holder 70 is in place with a capacitor 64 held in spring clips 72 and 74, the capacitor 64 will not only be held in position as described above, but also will be electrically connected in parallel circuit with contacts 26 and 36. That is, one terminal of capacitor 64 makes contact with spring clip 72 and is electrically connected via tab 82 to spring 42 and hence to arm 34 via rivets 44 and thus contact 36. The other end of capacitor 64 is in contact with spring clip 74 and thus is electrically connected via tab 84 to lug 46 and hence to plates 12 and and thus contact 26. Insulator 56, as will be seen, serves to insulate tab 82 and bolt 48 from lug 46.

The above detailed description is intended to be illustrative only. My invention is subject to various modifications, changes and the like without departing from the scope and spirit of it. Consequently, the limits of my invention should be determined from the claims appended hereto.

What is claimed is:

l. A unitized breaker point and capacitor assembly comprising a support plate, a breaker arm pivotally connected to said plate, a spring connected to said arm, a lug extending from said plate, a fastener connecting said spring to said lug, an insulator for electrically insulating said fastener and spring from said lug, a chip capacitor, a first tab connected to one side of said capacitor and a second tab connected to the other side of said capacitor, said first tab being disposed between said lug and insulator and said second tab being disposed adjacent said spring so that said fastener also holds said capacitor in place.

2. An assembly as set forth in claim 1 wherein a first contact is carried by said arm and a second contact is connected to said plate, said tabs connecting said capacitor in parallel circuit with said contacts through said lug, spring, arm and plate.

3. An assembly as set forth in claim 2 wherein said tabs support said capacitor in a position substantially within the perimeter of said plate and in close proximity to said arm so that said unitized assembly can be used in the space provided in a distributor for a breaker point set only.

4. A unitized breaker point and capacitor assembly comprising a support plate, a breaker arm pivotally connected to said plate, a first contact mounted on said plate, a second contact mounted on said arm and moveable into abutment with said first contact upon pivotal movement of said arm, a lug extending from said plate, a spring connected to said arm, a fastener connecting said spring to said lug so that said arm is biased to bring said second contact into abutment with said first contact, an insulator disposed to electrically insulate said fastener and spring from said lug, a chip capacitor and a capacitor holder adapted to removably receive said capacitor and including a first spring clip with a tab, a second spring clip with a tab and a rigid dielectric portion connecting said clips, said tabs being arranged so that one of said tabs is disposed in contact with said lug and the other of said tabs is disposed in contact with said spring, whereby said capacitor is connected in parallel circuit with said contacts and said fastener also holds said holder and capacitor in place within the perimeter of said plate and in close proximity to said arm. 

1. A unitized breaker point and capacitor assembly comprising a support plate, a breaker arm pivotally connected to said plate, a spring connected to said arm, a lug extending from said plate, a fastener connecting said spring to said lug, an insulator for electrically insulating said fastener and spring from said lug, a chip capacitor, a first tab connected to one side of said capacitor and a second tab connected to the other side of said capacitor, said first tab being disposed between said lug and insulator and said second tab being disposed adjacent said spring so that said fastener also holds said capacitor in place.
 2. An assembly as set forth in claim 1 wherein a first contact is carried by said arm and a second contact is connected to said plate, said tabs connecting said capacitor in parallel circuit with said contacts through said lug, spring, arm and plate.
 3. An assembly as set forth in claim 2 wherein said tabs support said capacitor in a position substantially within the perimeter of said plate and in close proximity to said arm so that said unitized assembly can be used in the space provided in a distributor for a breaker point set only.
 4. A unitized breaker point and capacitor assembly comprising a support plate, a breaker arm pivotally connected to said plate, a first contact mounted on said plate, a second contact mounted on said arm and moveable into abutment with said first contact upon pivotal movement of said arm, a lug extending from said plate, a spring connected to said arm, a fastener connecting said spring to said lug so that said arm is biased to bring said second contact into abutment with said first contact, an insulator disposed to electrically insulate said fastener and spring from said lug, a chip capacitor and a capacitor holder adapted to removably receive said capacitor and including a first sprIng clip with a tab, a second spring clip with a tab and a rigid dielectric portion connecting said clips, said tabs being arranged so that one of said tabs is disposed in contact with said lug and the other of said tabs is disposed in contact with said spring, whereby said capacitor is connected in parallel circuit with said contacts and said fastener also holds said holder and capacitor in place within the perimeter of said plate and in close proximity to said arm. 